Not sure where 15-16% total fees comes from?

Ebay fees for non-stores are 9.9%, paypal (domestic rates) is 30c per transaction plus 2.4%.... equals 13.3% of the total paid by the buyer plus 30c.

If you are within your 40 free listings then the insertion fee is waived.  After that there is a table of fees here:

http://sellercentre.ebay.com.au/ebay-for-business/about-store-packages.

You can also look out on these boards for listing specials, there is one going at the moment for non-stores of 150 free listings.  

With postage, at the moment there is a 10% discount special; a 500g bag is $6.48.  Of course there are many postage options at different rates.

Hope that helps.